Switch and method of controlling circuits



ay 36, 1944 H. L.. LAMBERT 2,34%,871

SWITCH AND METHOD OF CONTROLLING CIRCUITS Filed Sept. 22, 1939 @VENTQR1922773 Z. Lawzefi B/ CVI/Wfi m ATTORNEYS Patented May 30, g 1944 SWITCHAND METHOD OF CONT'BOILING CIRCUITS Barry L. Lambert, Enfield, N. Y.,assignor to Allen Wales Adding Machine Corporation, Ithaca,

Application September 22, 1939, Serial No. 296,124

26 Claims.

repeated openings or the circuit of the motor,

and when mercury was employed the governors could only be operatedsuccessfully when disposed in a single position. Such devices in use arefrequently mounted by the users in different inclined or angularpositions in violation of instructions, and this sometimes ailects thespeed at which the switch devices will open, and in some constructionsthe governors will not even workat all in more than a single limitedposition. When the position of the governor is changed, it sometimeshappens that the centrifugal force required to break or open the circuitis greater than when the device is operated in other positions, and thisis also objectionable.

An object of the invention is to provide an improved method ofcontrolling an electric circuit which will be relatively simple, andwhich will require a minimum of apparatus and servicing attention.

Another object of this invention is to provide an improved automaticelectrical switch, controlled by the speed of rotation of a rotatingelement,,and which switch will be simple, eflicient and inexpensive.

Another object of the invention is to provide an improved switch of theliquid or mercury type, the operation of which will be independent ofthe action of gravity, which will alter the circuit only by forcesgreater than gravity, and which may be operated equally well in allpositions.

Another object of this invention is to provide an improved switch devicefor controlling the speed of an electric motor which will not bedependent upon or operated by the action of gravity in limiting thespeed of the motor, and with which the circuit will not be broken bygravity in any position of the device, which will be relatively simple,compact, durable and inexpensive, and which will require a minimum ofmaintenance and attention in service.

Another object of the invention is to provide an improved speed governorswitch which will run equally well in any position, which will notrequire the use of pivoted weights, which will operate to control thespeed only in response to centrifugal forces and in which the influenceof gravity in affecting the opening of a circuit will be negligible,with which the circuit may be opened only by a force greater thangravity, with which there will be no burning of contacts, which willoperate for long periods of time without disintegration, damage orinjury to the circuit controlling parts, which will require a minimum ofservicing in use, and with which the speed at which the circuit will beopened may be varied and adjusted in a very simple and practical manner.

Other objects and advantages will be apparent from the followingdescription of two embodiments of the invention, and the novel featureswill be particularly pointed out hereinafter in connection with theappended claims.

In the accompanying drawing:

Fig. 1 is a longitudinal, sectional elevation through a speed governorof an electric motor, which has been constructed in accordance with thisinvention and in which the parts are shown as in the positions occupiedduring use, that is, during rotation;

Fig. 2 is a transverse, sectional elevation of the same, the sectionbeing taken approximately along the line 2-2 of Fig. 1;

Fig. 3 is a smaller, transverse, sectional elevation through the same,the section being taken approximately along the line 3--3 of Fig. 1 andillustrating the position of the mercury globule during rotation at aspeed below that at which the device is set to open the circuit of themotor;

Fig. 4 is a similar sectional elevation along the line 3-3 of Fig. 1 butshowing the position and shape of the globule of mercury at the time thecircuit is opened at a predetermined. speed; and

Fig. 5 is a transverse sectional elevation similar to Fig. 2 but showinga modification of the mounting of the contact mechanism on the rotatablemember.

In the embodiment of the invention illustrated in Figs. 1 to 4, theswitch device is illustrated as employed for controlling the speed of anelectric motor l0 having its drive shaft ll extending from one endthereof and directly mounting the governor. This motor It! may be of anysuitable type, whether operated by either direct or alternating current,or it may be a universal motor operable equally well on either type ofcurrent. The current for the motor is supplied from line wires L and Land controlled by any suitable this recess.

master controlling switch (not shown) in the usual manner. The line'wire L is broken, however one portion thereof at the break beingconnected to a brush l2, and the other portion thereof at the breakbeingconnected to a brush i3.

I suitable type is mounted on the end of the shaft II, and this memberl4 has a tubular boss l5 which fits over the end of the shaft II and issecured thereto'in any suitable manner such as by a set screw IS. Themember has two-end"""' faces which are transverse to the axisoffrotation of the shaft H. Upon one of [these end faces, such as theface towards the motor, a pair of collecting rings l1 and I8 aresecured. These rings are of metal, of difierent diameters, andconcentric with the axis of rotation of the shaft I I. They may bemounted on or anchored to the face of the member l4 in any suitablemanner (not shown). The brushes l2 and I3 bear upon the exposed endfaces of the rings I! and 18 so as to establish circuit connectionsthereto from the sections of the line wire L during the rotation of themotor. It will be understood that the brushes l2 and I3 may 'be of anysuitable typ but in the particular illustrated example,- th brushes l2and i3 ";are slidably received in the open end of tubular bushings l9which extend through a bar 20 of insulating material. This bar iscarried by studs 2| projecting from the 21 so as to forma tight fittherewith and thus form a tubular extension from the support 24. Thefree end of the tube 28 is closed by a plug or closure 29 of suitableinsulating material which preferably telescopes slightly within the endof the tube and also abuts against the outer end of the tube. A metalrod or bolt 30 has its head 3| countersunk in the disk or support 24 atthe face within the recess 23, the bolt extending approximatelycentrally through the tube 28 and through the closure or plug 29thereof. The outer end of this bolt 30 carries a nut 32 which whentightened draws the plug 23 into tightly fltting engagement with theouter end of th metals-tube,v

tub e upon the 13085 -27 o'f the plied, and the outer edge of thisconnector 33 is frame of the motor it. A spring-22 is disposed in eachbushing I9, .'under compression between I! or I8. The portions of theline wire L at the break are connected'at theouter ends of the bushings19 in any suitable manner, and through the latter to the brushes l2 andI3.

Th rotatable member I4 is provided in its outer end face with a shallowrecess 23 which is circular in shape but eccentricto the axis ofrotation of the shaft II, and Ya support or disk 24, preferably ofinsulating material, is mounted in The support 24 has acircularperiphery which approximately fits th circular recess .23, so asto provide a rotatable connection between the support 24 and member l4.The support or disk 24 is secured in the recess and clamped in any ofdiiferent possible rotary positions therein, in any suitable manner,such as by clips or clamping plates 25 which are adjustably secured tothe end face of the rotatable member I4, such as by screws 28' that passthrough the plates 25 and are threaded into the member l4. The plates 25overlie somewhat the recess 23, and the disk or support 24 i madeconnected by a flexible conductor or wire 34 to one of thecollectingrings, such as the ring l8, in any suitable manner. Similarly a flexiblewire or conductor 35 is connected at one end to the metallic tube 28 andat its other end to the other collector ring II. A globule 36 of liquidmercury is disposed within the chamber of the tube 28, and the globuleis of a size such that when it rests upon or abuts against the surfaceof the inner periphery of the tube 28 which is farthest from the axis ofrotation, it will Just nicely contact with and engage the rod 38 so asto form an electrical connection between the tube 28 and the rod 30.Such a position is shown by the position of the globule in full lines inFig. 1 and also in Fig. 3.

The globule should not fill the entire chamber of the tube, so that itcan expand in a direction endwise of the chamber, that is, in directionparallel to the axis of rotation, and it may also be free tov expand ina direction circumferentially of the tube 28. It will be understood thatin 'Fig. 1 the globule is shown as resting against the zone of the wallof the tube which is farthest from the axis of rotation, which is theposition it will occupy when the motor is operating. When the motor isnot running, how-' ever, the globule will drop .to the bottom of athicker than the depth of the recess, so that the plates 25, as theyextend over the recess 23. will overlap and bear upon the marginal edgeof the support 24. When the screws 26 are tightened, the plates 25 willdraw the disk or support 24 into the recess 23 and frictionally clamp itin any position in the recess into which it has been rotated.

The support or disk 24 has a cylindrical boss 21 projecting endwisetherefrom, eccentrically to the center of the disk or support 24 andhence eccentrically to the recess 23. A cylindrical, metal tube28 is;fitted at one end over the bos chamber of the tube 28, such as into theposition 1 shown by the dotted lines in Fig. 1 and designated A. Itwillbe noted that in the position A in Fig. l, the globule alsocompletes thecircuit between the tube 28 and the rod 30. If th position of the motoris varied so as to shift the tube 28 into different positions out ofhorizontalthe globule 36 will, during idleness of the motor, al-,,

ways maintain a contact between the tube 23 and the rod 30. For'example,if the tube 28 is tipped into an upright or vertical po'sitionsuch aswould be occupied if the shaft H :01 the motor 1 were disposedvertically, the globule 36 of mercury will rest against an end of thechamber of g the tube 28 and, because it still retains its globulevform, it will electrically connect the tube 28 and ;will function in thesame way, because, due to will remain in that zone under the influenceof centrifugal forces, at which time the forces of gravity on theglobule become substantially nil or negligible and may be substantiallydisregarded in controlling the speed of the motor or the operation ofthe switch. The globule of mercury has a high surface tension, so thatit tends to maintain its globular form when conflned against the wallzone of the tube 28 which is farthest from the axis of rotation, andthus will maintain a contact between the tube 28 and the rod 38 whilethe rotation of the shaft H continues. As the speed of rotation of theshaft ll increases, the intensity of the centrifugal forces acting onthe globule 36 of mercury and tending to overcome the surface tension ofthe globule and flatten it against the wall of the inner circumferenceof the tube 28, will increase, and when the rotating member has reacheda predetermined speed, this deformation or flattening of the globule ofmercury will be sufllcient to cause the globule to leave contact withthe rod 38. open the circuit in the line wire L and thus cut off theflow of current to the motor. The motor will then decrease in speeduntil the centrifugal forces acting on the globule decrease and allowthe globule to resume its former shape, due to surface tension acting onthe globule, and reestablish contact between the globule and the tube28. Thus current will flow to the motor only when the speed of the motoris below predetermined speed, and the action will be entirely automatic.

Owing to the completion and opening of the circuit through the mercuryglobule, there will be very litle arcing in the mercury globule, andsuch arcing as does occur cannot injure the mercury or the rod 30. Asusual in mercury contacts. the chamber of the tube 28 will preferably befilled with an inert gas, so that there is very little or no arcing whenthe circuit is opened, and any arcing that does occur will notmaterially injure the mercury or the rod 38. There will be no arcingbetween the globule and the tube 28 because they always remain incontact. It will be observed that since the mercury by centrifugal forcealways tends to seek the wall zone farthest from the axis of rotation,the governor will work satisfactorily in all different positions inwhich the motor, governor and the globule may be placed, and since theforces of gravity acting on the globule are relatively insignificantcompared with centrifugal forces acting on the globule, the action ofgravity will be negligible in its effect on the openng and closing ofthe circuit through the globule. The centrifugal forces which reallycontrol the closing and opening of the circuit at the globule duringrotation of the motor will not be materially modified by the influenceof gravity and will be equally effective and of the same value whetherthe governor is disposed in one position or another.

The position of the globule when it withdraws from contact with the rod38 is shown in Fig. 4 in full lines, and in Pg 1 by the dash lines B.The expansion or deformation of the globule, as it is flattened bycentrifugal forces, will be largely in directions parallel to the axisof rotation, because the globule is urged by centrifugal forces as faras possible from the axis of rotation, and any material expansion alonthe peripheral surface of the tube would carry it towards the axis ofrotation which is resisted by centrifugal forces. By rotating thesupport 24 within the recess 23 Lin .into different positions, theextent of eccentricity of the tube 28 with respect to the axis ofrotation may be varied, and since the centrifugal forces acting on theglobule and tending to flatten it and open the circuit varyproportionally to the radius of rotation of the globule about the axisof rotation, it will be seen that by varying the extent of eccentricityof the tube with respect to the axis of rotation, the speed at which thecircuit will be opened may be controlled and thus the speed of the motorequally controlled. A protective casing 81 may be carried by theperiphery of the rotatable member I and extending into enclosingrelation over the tube 28 and the other parts mounted on the outer endface of the member ll so as to avoid any danger of electrical shock toany one through accidental contact with the conductors, and also toprotect against injury to any one who might otherwise be hit by theeccentrically mounted parts on the member I 4.

In the embodiment of the invention illustrated in Fig. 5. theconstruction is similar to that shown in Figs. 1 to 4, except that thesupport 2la, which corresponds to the support 24 of Figs. 1 to 4,instead of be ng rotatably mounted in the recess 23, is in the form ofan arm which is pivoted to the member I near one edge thereof, such asby a screw 38, so that by swinging the support 24a about the pivot screw38, the tube 28 and the parts associated therewith may be shifted todifferent distances away from the axis of rotation of the shaft II. Thefree end of the arm or support 24a is provided with a slot 39 whosecenter of curvature is at the pivot 38, and a clamping screw passesthrough this slot 39 and isthreaded into the rotatable member l4, sothat by tightening the screw 48, the arm or support 24a may be clampedin different adjusted positions on the member I4. A suitable scale 8|may be provided on the face of the member l4, and the arm or support 24amay have a pointer 42 which cooperates w'th the scale to aid one insetting the tube 28 to any extent of eccentricity on the member l4within the limits provided for. After an adjustment of arm 2411 thetightening of the screw 40 will maintain that adjustment.

In both of the particular embodiments of the invention which have beendescribed and illustrated above, the liquid globule is described as ofmercury because the globule must be of electricity conducting materialwith a substantial surface tension and should not wet the surfaces ofthe chamber against which it abuts. While other liquids having similarproperties may be employed, liquid mercury is preferable for thispurpose because it has an unusually high surface tension and tends toform a more or less globular form when a relatively small quantity isplaced on a surface or in a chamber. The word globule is intended torefer to a relatively small body of liquid which has sufficient surfacetension to draw the body into a somewhat globular or generally ball-likeform when placed on a surface which it will not wet, in distinction tothe use of a relatively larger quantity which in effect forms a bath inthe chamber and which, because of the relatively larger quantity,conforms to the shape of the chamber instead of forming the more or lessball-like shape. By the use of the globule, or the mass which maintainsits own shape which is different from that of the chamber in which it isplaced, the governor will work in any position and at a much higherspeed than any generally similar governor utilizing a bathtype body ofcontact liquid.

In a switch employing a bath-type body of contact liquid, a relativelylarger body of conducting liquid such as mercury is disposed in acircular or cylindrical container, and when the container is rotatedabout an axis concentric to the container, the liquid immediately formsa skin-like, continuous film along the inner surface of the container,and either connects or disconnects electrodes projecting into'thechamber. In such cases any appreciable speed will immedi ately cause theskin-like surface to form, thus being useful only for relatively lowspeeds, but by the use of the globule it is possible to rotate thegovernor at a much higher speed before it alters the circuit. By havingthe chamber in which the globule is placed eccentric to the axis ofrotation, the globule or liquid body tends to remain together in thesame body, instead of spreading out as a skin-like coating, andmaintains more or less its same form, except as modified by thecentrifugal forces which tend to flatten the globule against thesurface,

It will be understood that the wall against which the mercury globule isconfined during the rotation, should have a greater length or dimensionin at least one direction than the width of said globule so that theglobule when flattened mayexpand and thus draw away from the centralelectrode 30 which is spaced from the other electrode such as theconducting surface. As a matter of simplicity, the tube 28 is formedentirely of conducting material, and forms one of the conductors orcontact terminals within the chamber, the clamping rod 30 being utilizedas the otherconductor, This arrangement is advantageous and provides avery simple, inexpensive and practical arrangement, but it will be un-'derstood that the body of' the tube may be of other material, with aconducting surface disposed along the inner surface thereof,particularly in the part occupied by the globule during rotation, whichwould be the wall zone which is farthest from the axis of rotation. Byhaving the conducting surface extend around substantially the entiresurface of the chamber of tube 28, the circuit will always be closedwhen the mo tor stops, regardless of the position of the motor.

When a bath is rotated eccentrically it assumes its final shape havingan inner surface concentric with the axis of rotation just as soon asthe forces of gravity become negligible. Rotation at a higher speedwould scarcely alter the shape of the bath. Thus a bath rotatedeccentrically, if practical at all, could be used only at very lowspeeds of rotation to open and close a circuit, and the forces ofsurface tension would have no appreciable effect. Any conducting liquid,regardless of whether its surface tension was high or low, would givethe same results with a'rotating bath, whether rotated concentrically oreccentrically;

It will also be understood that various other changes in the details,materials and arrangements of parts, which have been herein describedand illustrated in order to explain the nature and principle of theinvention, may be made by those skilled in the art within the principleand scope of the invention, as expressed in the appended claims.

I claim as my invention:

1. A switch device for controlling an electric circuit which comprises arotatable member, a hollow element rotatable with said member and havingspaced, opposing, electrically conducting surfaces in the chamberthereof and insulated from one another, one of said surfaces formingthat portion of the surface of said chamber approximately farthest fromthe axis of rotation of said member and being formed of a material whichis not wet by liquid mercury, the other of said conducting surfacesbeing disposed nearer said axis than said one surface, means forconnecting said surfacee;.to terminals of said circuit during rotationof said element with said member, and a globule of mercury disposed insaid chamber and of such size that its surface tension draws it into agenerally ball-like form independently of the forces of gravity and thatit will engage with and electrically connect said conducting surfaceswhen said globule is supported by said surface portion farthest fromsaid axis of rotation and is subjected only to the action of gravity andinsuflicient to cover said one surface, whereby when said element isrotated about said axis, the centrifugal forces acting on said globulein opposition to the forces of surface tension will tend to flatten saidglobule against the outermost of said' conducting surfaces and pull awayfrom said axis while said globule remains relatively stationary on saidsurface portion farthest from said axis, and separate from the other ofsaid conducting surfaces to open said circuit at said globule by suchflattening while in the same relative position on said surface portion.

2. A switch device for controlling an electric circuit whiclrcomprises ahollow element Having spaced, electrically conducting, circuitconductors in the chamber thereof and insulated from one another, aglobule of mercury disposed in said chamber, of a size to engage withand electrically connect said conductors when said globule is subjectedonly to the action of gravity and insufllcient to fill said chamber, andto retain its ball-like shape, and means mounting said element forrotation about an axis eccentric to said globule when said globuleconnects said conductors, said chamber having that portion of itsencircling surface wall which is engaged by said globule when theglobule connects said conductors, disposed farthest from said axis ofall portions of said wall, and farther from said axis than one of saidconductors, and also having a shape and size enabling said globule toretain its globular form but to flatten and thicken during its rotation,whereby when said chamber and globule are rotated about said axis, saidglobule will tend to flatten out against said wall portion whileremaining relatively stationary thereagainst and, when a predeterminedspeed of ro tation is reached, separate from said one of said conductorsand open the electric circuit between said conductors.

3. A' switch device for controlling an electric circuit which comprisesa hollow element having spaced, electrically conducting, circuitconductors in the chamber thereof and insulated from one another, aglobule of mercury disposed in said chamber, of a size to engage withand electrically connect said conductors when said globule is subjectedonly to the action of gravity and insufiicient to fill said chamber, andmeans mounting said element for rotation about an axis eccentric to saidglobule when said globule connects said conductors, said chamber havingthat portion of its encircling surface wall which is engaged by saidglobule when the globule connects said conductors, disposed farthestfrom said axis of all portions of said wall, and farther from said axisthan one of said conductors, and also, having a shape and size enablingsaid globule to retain its globular form but to flatten and thickenduring its rotation, whereby when said chamber and globule are rotatedabout said axis, said globule will tend to flatten out against said wallportion and, when a predetermined speed of rotation is reached, separatefrom said one of said conductors and open the electric circuit betweensaid conductors, said chamber being adjustable on its mounting todifferent distances from said axis to vary the speed at which saidglobule will separate from said one of said conductors and thereby opensthe circuit between said conductors.

4. An improved switch of the type having two circuit controllingterminals to be connected and disconnected, and comprising a chamberhaving one wall zone, a globule of mercury confined in said chamber andengageable with said wall zone, and of a size to retain a generallyball-like shape by the action of its surface tension, said wall havinggreater length in one direction than the width of said globule, meansfor rotating said chamber and globule about an axis eccentric to saidchamber but with said wall zone farther from said axis than the otherzones of said wall, whereby said globule will be confined against saidwall zone and without translation therealong and flattened thereon bycentrifugal forces due to such rotation, and spaced conducting terminalsinsulated from each other and disposed in said chamber for engagementwith said globule when said globule is confined against said wall zoneand subjected to the influence of gravity alone, and one of them spacedfrom said wall zone towards said axis for disengagement from saidglobule when the latter is flattened against said wall by centrifugalforces created by said rotation at a predetermined speed while remainingin the same position on said wall zone.

5. An improved switch of the type having two circuit controllingterminals to be connected and disconnected, and comprising a chamberhaving one wall zone, a globule of mercury confined in said chamber, andof such size that its surface tension overcomes the action of gravityand draws the globule into generally ball-like shape, and engageablewith said wall zone, said wall having greater length in one directionthan the width of said globule, means for rotating said chamber andglobule about an axis eccentric to said chamber but with said wall zonefarther from said axis than the other zones of said wall, whereby saidglobule will be confined against said wall zone and, while remainingrelatively stationary on said wall zone, flattened thereon bycentrifugal forces due to such rotation, and spaced conducting terminalsinsulated from each other and disposed in said chamber for engagement ofboth of them with, and disengagement of at least one of them from, saidglobule when said globule is confined against said wall zone andsubjected to different centrifugal forces, due to differentpredetermined speeds of rotation, that change its shape.

6. An improved switch comprising a rotatable member, a hollow elementmounted on said member for rotation therewith and having anapproximately cylindrical chamber therein with its longitudinal axisapproximately parallel to and at one side of the axis of rotation ofsaid member. a conductor rod extending endwise through said chamber, thewall forming the cylindrical chamber being of metal, and the ends ofsaid chamber being of insulating material, collecting rings on saidmember, one connected to said metal cylindrical wall and the otherconnected to said rod, brushes bearing on said collecting rings forestablishing circuit connections to said metal cylindrical wall and saidrod during their rotation with said member, and a globule of mercury insaid chamber of a size to contact said rod and said cylindrical wallwhen said element is quiet but free to move endwise in said cylinder andalso of such size that its surface tension overcomes the action ofgravity and draws the globule into a generally ball-like shape, wherebywhen said member is rotated about said axis, the mercury while confinedagainst the outer, cylindrical wall of said chamber will provide aconnection between said rod and the metal cylindrical wall whileconfined against the portion of the cylindrical wall farthest from theaxis of rotation, but will pull away from said rod and open the circuitthrough said chamber when the centrifugal forces acting on said mercuryare suflicient to flatten it against the cylindrical wall in oppositionto its surface tension until it leaves contact with said rod.

7. An improved switch comprising a rotatable member, a hollow elementmounted on said member for rotation therewith and having anapproximately cylindrical chamber therein with its longitudinal axisapproximately parallel to and at one side of the axis of rotation ofsaid member, a conductor rod extending endwise through said chamber, thewall forming the cylindrical chamber being of metal, and the ends ofsaid chamber being of insulating material, collecting rings on saidmember, one connected to said metal cylindrical wall and the otherconnected to said rod, brushes bearing on said collecting rings forestablishing circuit connections to said metal cylindrical wall and saidrod during their rotation with said member, and a globule of mercury insaid chamber of a size to contact said rod and said cylindrical wallwhen said element is quiet but free to move endwise in said cylinder,whereby when said member is rotated about said axis the mercury willprovide a connection between said rod and the metal cylindrical wallwhile confined against the portion of the cylindrical wall farthest fromthe axis of rotation, but will pull away from said rod and open thecircuit through said chamber when the centrifugal forces acting on saidmercury in opposition to the surface tension of the globule aresufficient to flatten it against the cylindrical wall until it leavescontact with said rod, said element being adjustable on said member tocarry said chamber to different extents away from said axis of rotationso as to vary the centrifugal forces acting on said mercury and tendingto flatten it, and thus vary the speed of rotation at which the circuitis interrupted.

8. A switch device for controlling an electric circuit which comprises arotatable member of insulating material, a support of insulatingmaterial adjustably secured to a face of said member which is transverseto the axis of rotation of said member and adjustable thereon in adirection crosswise of said axis, a metal cylindrical tube mounted onthe end face of and closed by said support so as to extend therefrom ina direction parallel to said axis, an insulating closure for the outerend of said tube, a metal rod extending approximately centrally of saidtube between said support and closure and clamping the closure to tubeand the tube to the support, a P

collecting rings carried by said member, a flexible conductor connectingone of said rings with said rod, another flexible conductor connectingthe v metal tube to the other of said rings. brushes bearing on saidrings to form electrical connections therewith during rotation of saidmember,

and a globule of mercury in said tube of a size of a predeterminedspeed, said hollow element be-- ing adjustable on said member in adirection crosswise of the axis of rotation so as to carry saidelementlaterally toward and from said axis to different extents so as to varythe speed at which the centrifugal forces will be suflicient to separatesaid globule from said conductor, by

' centrifugal forces. v

to contact said rod but not fill said chamber when I subjected only tothe action of gravity and when said tube is in an approximatelyhorizontal position, whereby said mercury will normally complete aconnection between said-brushes through the chamber of said tube, butwill tend to flatten against a wall zone of said tube by centrifugalforces acting on the globule while said member is rotating, and when apredetermined speed is reachedthe flattening of the globule will besuflicient to draw away from said rod and open the circuit between thebrushes. I

9. A switch device for controlling an electric circuit which comprises arotatable member, a hollow element mounted on said member for rotationtherewith, said element having a cylindri-- cal chamber therein whoseaxis extends approximately parallel to the axis of rotation of saidmember but located at one side thereof, said chamber having a conductingsurface extending along the interior face of the cylindrical wallthereof, a conductor extending approximately through the center of thechamber of said element in an endwise direction and approximatelyparallel to'saidcylindrical wall but spaced therefrom, a globule ofmercury disposed in said chamber of a size to touch said conductor butnot fill said chamber when the globule of mercury is resting on thecylindrical wall of the chamber, and is under the influence of gravityalone, and

when the axis of the chamber is approximately horizontal, and means forestablishing circuit connections to said conductor and to said con- 1ducting surface during their rotation with said member, whereby themercury normally provides an electric connection through said chamberbut flattens out and leaves contact with said conductor when subjectedto the centrifugal forces created by the rotation of said member inexcess of a predetermined speed.

10. A switch device for controlling an electric circuit which comprisesa rotatable member, a

hollow element mounted on said member for roparallel to saidcylindricalwall but spaced there-- from, a globule of mercury disposedin said chamber of asize to touch said conductor but not fill'saidchamber when the globule of mercury v .is resting on the cylindricalwall of the chamber, and is under the influence of gravity alone, and

when the axis of the'chamber is approximately horizontal, and means forestablishing circuit connections to said conductor and to saidconducting surface during their rotationfwith said member, whereby themercury normally provides an electric connection through said chamberbut flattens out and leaves contact with said conductor when subjectedto the centrifugal forces v created by the rotation of said member inexcess 11. A switch device for controllin an electric circuit whichcomprises a member of insulating material having a pair-.of parallelfaces and mounted for rotation about an axis normal to said faces, apair of collecting rings on one of said faces, a support of insulatingmaterial secured against the other face and having a cylindrical bossprojecting therefrom in a direction parallel to said axis, a metallictube fitting over and closed by said boss, a plug of insulating materlalclosing the other end of said tube, a metallic. rod extending betweensaid support and plug for drawing the same toward one another andclamping said plug and tube to said support, and effectapproximatelyhorizontal and the globule is resting on the portion of the cylindricalzone of said tube which is the farthest from the axis of rotation andwhich globule is shorter in length than the chamber in said tube,whereby said globule may expand endwise when flattened by centrifugalaction and' when so expanded endwise will withdraw from contact withsaid rod and open the circuit between said rings.

12. A switch device for controlling an electric circuit which comprisesa member of insulating material having a pair of parallel faces andmounted for rotation about an axis normal to said faces, a. pair ofcollecting rings on one of said faces, a support of insulating materialsecured against the other face and having a cylindrical boss projectingtherefrom in a direction parallel to said axis, a metallic tube fittingover and closed by said boss, a plug of insulating material closing theother end of said tube, a metallic rod extending between said supportand plug for drawing the same toward one another and clamping said plugand tube to said support, and effecting a closure of the chamber of saidtube, a conductor. connecting one end of said rod and one of said rings,a conductor connecting the tube and the other of said rings, brushesbearing on said rings during said rotation, and a globule of mercurydisposed in the chamber of said tube and of a size to touch said rodwhen said tube is approximately horizontal and the globule is resting onthe portion of the cylindrical zone of said tube which is the farthestfrom the axis of rotation and which globule is shorter in length thanthe chamber in said tube, whereby said globule may expand endwise whenflattened by centrifugal action and whenso expanded endwise will with;-

draw from contact with said rod and open the of different positions inwhich said tube is dis-- posed at difierent distances from the axis ofrotation, whereby the speed at which the globule flattens and interruptsthe circuit through said tube may be varied selectively .by the placingof said tube in different ones of said positions.

13. A switch device for controlling an electric circuit which comprisesa pair of spaced conductors in series in said circuit, a globule of aconducting liquid having a high surface tension and of such size thatits surface tension overcomes the forces of gravity thereon and holds itin a generally ball-like shape, supported in contact with one of saidconductors and making contact with the other of said conductors byvirtue of its globular shape due to its surface tension overcoming thenormal leveling action of gravity, and means for changing the shape ofsaid globule substantially in opposition to the forces of surfacetension in a manner to break contact of said globule with one of saidconductors, which said globule remains relatively stationary withrespect to the other of said conductors.

14. A switch device for controlling an electric circuit which comprisesa pair of spaced conductors in series in said circuit, a globule of aconducting liquid having a high surface tension and of such size thatits surface tension overcomes the forces of gravity thereon and holds itin a generally ball-like shape, disposed to normally make contact withsaid conductors by virtue of the globular shape of said liquid due toits surface tension overcoming the normal leveling action of gravity andto break contact with at least one of said conductors when the shape ofsaid globule is changed in one dimension, and means for changing theshape of said globule in said one dimension by modification of forcesopposing the action of the forces of surface tension while the globuleremains otherwise in the same relation to said conductors.

15. The improved apparatus for controlling an electric circuit betweentwo spaced conductors of said circuit which comprises said conductors, aglobule of mercury of such size that its surface tension draws it into agenerally ball-like shape, disposed in contact with said conductors tocomplete a circuit therebetween, a wall spaced from at least one of saidconductors and abutting said globule and along which said globule mayexpand in at least one direction and of a material which said mercurywill not wet, and means for rotating said wall, globule and conductorsabout an axis eccentric to said wall and globule and thereby creatingcentrifugal forces tending to flatten said globule against said wall,without dividing said globule or changing its position on said wall, andwhich when a predetermined speed of rotation is reached, will flattensaid globule sufficiently to separate said globule from contact with atleast one of said conductors to open said circuit.

16. The improved apparatus for controlling an electric circuit betweentwo spaced conductors of said circuit which comprises said conductors, aglobule of mercury of such size that its surface tension overcomes theforces of gravity and draws it into a generally ball-like shape,disposed in contact with said conductors to complete a circuittherebetween, a wall spaced from one of said conductors and abuttingsaid globule and along which said globule may expand in at least onedirection and of a material which said mercury will not wet, and meansfor rotating said wall, globule and conductors about an axis eccentricto said wall and globule and thereby creating centrifugal forces tendingto flatten said globule against said wall, without dividing said globuleor changing its relative position upon said wall,

and which, when a predetermined speed of rotation is reached, willflatten said globule sumciently to separate said globule from contactwith at least one of said conductors to open said circuit, said meanshaving a portion adjustable to vary the degree of eccentricity of saidglobule and wall with respect to said axis and thereby vary the speed ofrotation at which said globule separates from said one of saidconductors.

17. The improved switch which comprises a free globule of a liquidhaving substantial surface tension and of such a size that its surfacetension overcomes the action of gravity and draws the globule into agenerally ball-like form, a wall of a material not wet by said liquidand against which said globule is disposed and along which it may expandin at least one direction, means for flattening said globule againstsaid wall and releasing it to cause lateral distortions of said globuletending to expand and contract it in said one direction, while saidglobule remains undivided and in the same relative position on saidwall, and conducting means disposed to be connected and disconnected bysuch distortion of said globule.

18. The improved apparatus for controlling an electric circuit.betweentwo spaced conductors which comprises said conductors, a globule ofliquid having a surface tension and such size that the forces of surfacetension acting thereon overcome the action of gravity normally tendingto flatten the globule and maintain the globule in a somewhat sphericalshape, a support for disposing said globule in a position to make andbreak contact with said conductors when the shape of said globule ischanged, and means for distorting said globule in shape, in oppositionto its surface tension, to different extents from its somewhatspherical, lobular shape while it remains undivided and in the sameposition on said support by applying flattening forces opposing thesurface tension forces without destroying said globular form, wherebysaid conductors may be electrically connected and disconnected solely bythe varying distortion of said globule.

19. The improved apparatus for controlling an electric circuit between apair of conductors in response to speed, which comprises said conductorsof a material not wet by mercury, a surface of a material not wet bymercury, a globule of mercury of such size that its surface tensionovercomes the forces of gravity acting thereon and draws said globuleinto a somewhat ball-like form when freely supported on said surface,disposed on said surface with freedom to flatten thereon, and in aposition to connect and disconnect said conductors as said globulechanges its globular form, and means for subjecting said globule whilesaid globule retains its same position on said surface against which itis disposed to centrifugal forces dependent upon said speed whichdistort said globule into different degrees of flattening without lossof its globular form, depending in extent of flattening upon the size ofsaid centrifugal forces, whereby the connection and disconnection ofsaid conductors by said globule will be responsive to said speed.

20. An improved electric switch comprising a globule of'mercury of suchsize that its surface tension overcomes the forces of gravity and drawsit into a generally ball-like form, means for flattening said globule todifferent extents from its normal ball-like form without dividing it, inopposition to its surface tension, and circuit means including aconductor disposed to be engaged with and disengaged from said globuleduring and only because of changes in the shape of said globule causedby said means and said surface tension, and while said globule is as amass relatively stationary with respect to said conductor.

21. A mercury tube switch for centrifugal operation comprising aconstant diameter tubular metallic envelope, a rod-like electrodeinsulatedly supported by the envelope and extending axially into andalong substantially the entire length of the envelope, an insulatingmember surrounding saidelectrode adjacent one end of the envelope; meansfor revolving the switch; means mounting the switch with its axis fixedsubstantially parallel to and eccentrically of the axis of revolution ofsaid revolving means and a limited quantity of mercury in said envelope;whereby said mercury may tend to form a globular mass at any positionalong said envelope at one side of said insulating member and normallybe in contact with said electrode to completea circuit between theelectrode and the envelope, and upon revolution of the switch bodilywith axis parallel to the axis of revolution, said mass will flattenand'withdraw from said electrode contact.

22. A mercury tube switch for centrifugal operation comprising a sealed,tubular, metallic envelope; a rod-like electrode insulated and supportedfrom the envelope extending axially into and substantially throughoutthe entire length of the envelope; means for revolving the switch; meansmounting the switch with its axis fixed substantially parallel to andeccentrically of the axis of revolution of said revolving means; andmercury in the envelope limited in quantity to form normally a localizedmass in any position along the envelope tending to assume a globularform suflicient in depth to contact both the envelope and the electrode;whereby upon bodily revolution of the switch may cause at a criticalspeed a flattening of the mercury mass to'break said contact.

not wet by it and against which it is confined,

means forrotating said chamber about an axis eccentric to said chamber,to create centrifugal forces on said body that will confine said body 1against the portion of said interior surface farthest from said axis andto flatten said body, while for establishing circuit connections to saidconducting means as the chamber rotates.

24. The electric switch substantially as set forth in claim 23, andmeans for adusting said chamber relatively to said axis to vary thedegree of eccentricity of said chamber and thereby vary the speed ofrotation of the chamber at which said centrifugal forces will change theshape of said body sufilciently to make or break a circuit therethrough.

25. An electric switch comprising a closed chamber filled with an inertatmosphere and having an interior surface of a material not wet bymercury, means for rotating said chamber about an axis eccentricthereto, a body of mercury within and only partially filling saidchamber and of such size that a substantial portion thereof is drawn byits surface tension away from the zone of said surface against whichsaid body may be confined, whereby when said chamber is 'so rotated saidbody will be confined by centrifugal forces, relatively immovablyagainst that portion of said interior surface which is farthest fromsaid axis, a conductor disposed within said chamber in a position tocontact with and separate from said body as the latter changes its shapebeyond selected limits, with changes in speed of rotation, under theopposing actions of centrifugal forces and surface tension, and meansfor including electric-ally in series, said body of mercury and saidconductor.

26. The switch substantially as set forth in claim 25, and said rotatingmeans including a mounting'for said chamber by which said chamber may beshifted toward and from said axis to vary the speed at which saidmercury and con.- ductor engage or separate.

' HARRY L. LAMBERT.

